Coronary Computed Tomography Angiography: Patient-related factors determining image quality using a second-generation 320-slice CT scanner

Purpose: To investigate the diagnostic confidence of Coronary Computed Tomography Angiography (CCTA) and the effect of patient-related factors on CCTA image quality using a second-generation 320-slice scanner. Methods and results: 200 consecutive patients (mean age 60 +/- 12 years; 109 men) prospectively underwent CCTA. The mean body mass index (BMI) was 27.1 +/- 4.9 kg/m(2); the median heart rate (HR) was 60.0 (interquartile range (IQR), 53.9-66.1) beats perminute (bpm). The median segment's diameterwas 2.8 (IQR, 2.2-3.4) mm. For each coronary segment >= 1.5 mm in diameter, two readers scored: diameter narrowing as < or >= 50%, overall diagnostic confidence and motion-related image quality, with interobserver agreement kappa-values of 0.89, 0.91 and 0.61 respectively. Seventy-nine of the 2505 evaluated segments (3.2%) had non-diagnostic image quality because of coronary calcifications (66/79; 83.5%), stent-(6/79; 7.5%), pacemaker- (2/79; 2.5%) or motionrelated artifacts (5/79; 6.5%). The effect of patient-related factors onmotion-related image quality was investigated by multinomial logistic regression in 181 patients with calcium score (IQR, 0-446.5). Increasing coronary diameterwas the most improving image quality factor (odds ratio (OR), 1.8637; p < 0.001), marginally followed by lower HR (OR, 0.9547; p < 0.001) and calcium score (OR, 0.9997; p = 0.04). Gender (p = 0.70), age (p = 0.24) and BMI (p = 0.45) did not affect image quality. Conclusion: Using a second-generation 320-slice scanner, CCTA diagnostic confidence is predominantly affected by coronary calcifications, whereas motion-related image quality is non-diagnostic only in exceptional cases and mainly influenced by the coronary diameter. For future developments, our study findings therefore suggest greater requirements concerning spatial resolution and calcium-related artifact removal than concerning temporal resolution, especially to improve diagnostic confidence in patient groups with smaller coronary diameters. (C) 2016 Elsevier Ireland Ltd. All rights reserved.